The invention relates to a system for distributing television signals to a plurality of user installations, which system comprises
an assembly of several different satellite television signal sources, PA1 a terrestrial television signal source, PA1 at least a cable distribution network serving the users on the basis of the assembly of signal sources, PA1 at least a branching element allocated to a group of user installations and having a plurality of outputs each coupled to one of the installations of the group, a plurality of inputs each coupled to one of the cables of the distribution network, and switching means whose number is equal to the number of its outputs, each switching means being assigned to one of the outputs for selecting one of the inputs of the branching element and connecting it to the relevant output, this selection being made for each of said means as a function of a control signal received by the corresponding user installation.
Such a system serving a group of users from communal aerials is used, for example in a building comprising a plurality of apartments. Such a system is known as "MATV" to those skilled in the art.
The conventional MATV systems authorize the user to make a selection from several broadcasts by tuning to one or the other carrier frequency. On the basis of frequencies ranging between 950 and 1750 MHz, for example in the case of signals received from a satellite by means of a converter (low noise converter, or outdoor unit) which supplies a signal at a frequency in this range of frequencies, with channels having a width of approximately 30 MHz, it is possible to distinguish 24 different channels. Nevertheless, this number is insufficient, considering that, for example a satellite assembly such as "Astra" has already more than 24 channels.
German utility model DE-U-9 108 899 (Mikroelektronik Neuhaus GmbH) describes a system using two signal sources H and V corresponding to two polarizations from one and the same satellite and, for serving a plurality of users, it comprises, step by step in a two-cable distribution network, branching elements having two inputs (one for each polarization), each element selecting one of the two inputs as a function of the value of a control voltage received by the receiver. This document describes only the case of the two polarizations and does not suggest any means which may be used in the case where, for example it is desirable to receive a plurality of satellites.